SH 657 456 (top entrance)
I have forgotten … if someone would post them this can be updated.
No known permission required.
Full SRT, Buoyancy aid (lifejacket), pulley for the zip line, dinghy, rope
Unknown but extensive
Unknown but water is present (in great depth) in some chambers although this is not known to rise to flood.
Slate Mine. Extensive caverns. Multiple levels. Abseils, Prussocks, lakes (flooded chambers), zip lines, challenging bridges (as in there is not much left of them)
A huge complex of slate workings.
A very popular through trip due to it’s sporting nature and full array of skills needed.
There are a number of entrances and it is possible to enter an adit low down in Croesor and walk through to the back entrance without the use of any equipment at all (except a lamp of course). The more popular route is to enter at the top and work through down two pitches, across a zip line, across a lake (once by suspended ladder which is now on the floor of the lake due to part of the ceiling collapsing onto it), across two bridges and another lake by dinghy and then a prussock up to finally come out of the back of the mountain.
Beyond this through trip there are a great many adits and passages to explore.
It is also worthy of note that a large amount of the system has partly collapsed (the ceiling) and is likely to continue to do so.
A great many remain unexplored
Release the Kraken .....